Motor vehicle suspension systems have an inherent problem that results in various compromises. Vehicle suspension systems are generally designed to avoid obstacles anticipated to be in the vehicle's path. Some vehicles, such as off-road vehicles, are designed with a high ground clearance to avoid obstacles encountered in rugged terrain, while other vehicles are designed with low ground clearance for high speed performance and/or sportier appearance. Ground clearance is the amount of space between the base of an automobile tire and the underside of the vehicle; or the shortest distance between a flat, level surface, and any part of a vehicle other than those parts designed to contact the ground (such as tires, tracks, skis, etc.). The benefits of low ground clearance and lower vehicle height are numerous and include less wind resistance, better fuel economy, better acceleration, better cornering, and better braking. Another significant advantage of low ground clearance is that it allows for better aesthetics such as providing a lower, sleeker, and sportier appearance that is desired by many drivers.
Many modern vehicles are designed and built with low ground clearance for the sportier appearance. Vehicle owners also lower their vehicles, through after-market modification, for enhanced performance, fuel economy and sportier appearance. One of the most common ways to lower a vehicle is through the use of a coilover, a vehicle suspension device that incorporates a coil spring positioned over and around a shock absorber shaft that is connected to a shock absorber body. Use of a coilover allows for a limited amount of height adjustment by adjusting the height of the coil spring's lower mounting point.
Reducing a vehicle's ground clearance height frequently results in undesired contact (collisions or scraping) between the vehicle and obstacles in the vehicle's path, such as speed bumps and sloping driveways. Unfortunately, when contact occurs, the vehicle is often damaged from the contact.
In the past, other vehicle lift systems have been developed, but they fall short of providing an adequate solution for many reasons. For example, some lift systems are designed and built to be vehicle-specific and are not readily adaptable to other vehicles. On the other hand, lift systems designed to fit a variety of vehicles often require the removal or replacement of existing components, resulting in added costs for the replacement components and loss of performance from the removal of critical or beneficial existing components. Such removed components may include coil springs, dust sleeves and bump stops.
Some prior art lift systems employ pressurized rubber air bags or air sleeves to replace coil springs in a suspension system. These systems do not retain the performance characteristics and benefits of metal coil springs, and incur the added cost of replacing the existing shock absorbers and/or metal coil springs with air bags or air sleeves. Moreover, components in lift systems that use metal coil springs may be so tall or thick that they do not fit into vehicles with the existing suspension springs. In such cases, the coil springs must be replaced with shorter springs resulting in a loss of suspension performance from the shorter spring.
Prior art lift systems also use hollow double-walled cylinder designs having concentric inner and outer cylinder walls. This design is complicated, more costly to manufacture, and more difficult to protect against dust and contaminants. These systems are also less efficient in the use of stored air pressure.
Prior art lift systems also do not typically provide dust shields (for the inner cylinder walls, outer cylinder walls, and/or the shock absorber shaft) to reduce contamination and wear on these surfaces and their seals attached thereon.
Still other prior art lift systems also have reduced pressurized surface areas on which the piston can act, resulting in inefficient use of power and the need for a larger storage tank to hold the compressed air (or other fluid), which is used to lift a vehicle. The tank required may reduce storage space, or even be so large that it cannot fit into many vehicles in a practical manner, and therefore is not able to be used in those vehicles.
Prior art lift systems that use bump stops, typically do so in a manner that reduces the effective pressurized area above the bump stop, making the system less efficient and requiring more air pressure and/or stored pressurized air to operate. They also do not provide a means for having the bump stop travel in tandem with the piston.
Prior art lift systems also do not have an adjustable, automated activation system that automatically senses obstacles in a vehicle's path and raises or lowers the vehicle based on the vehicle's proximity to the obstacles and its speed.
Other lift systems use components, such as large pneumatic cylinders or large air tanks that are often too large to install into many vehicles. These larger components also add undesirable weight to the vehicle, thus decreasing vehicle performance and efficiency.
Other systems that use compressed air tanks may also allow condensation (water) in the air tank to be passed through the air outlet port under certain driving conditions, which may cause surges of the water (surge water). Examples of such conditions include acceleration, braking and cornering. The surge water that passes through the air lines to the valves, pressure sensors, cylinders and other components has detrimental effects on these components.
Some other systems use hydraulic pumps and pressurized liquid to raise the vehicle, and use hollow double-walled cylinders having concentric inner and outer walls. This type of system is less efficient and requires significantly higher operating pressures to be effective. Hydraulic systems also require more costly hydraulic pumps and/or tanks filled with heavy hydraulic fluid and have the risk of fluid leaks and/or oil spills.
Hydraulic systems that have the cylinder and pistons fitted to the bottom of the spring located around the body of the shock absorber add undesirable unsprung weight to the suspension, thus reducing the performance of the suspension.
Hydraulic systems also pump fluid only when it is needed to lift a vehicle. Thus, they are slower acting systems that require strong pumps to raise a vehicle with enough speed to be effective. This means they draw higher amperage on a vehicle's electrical system. Further, because hydraulic systems typically raise vehicles slowly, they are not practical to use in many driving situations.
Prior art lift systems include: Umbrella Auto Design, Roberuta, Top Secret, Mode Parfum, Skipper, KW Hydraulic Lift System, Tech-Art, Ram Lift Pro, Phantom VIP, Stance-Solutions, Air Force, Air Lift, and Accuair.
It is an object of the present invention to provide an affordable lift system that is adaptable to a large variety of vehicles.
It is another object of the present invention to provide an efficient lift system that only requires small pressurized cylinders and storage tanks.
It is a further object of the present invention to eliminate or reduce the effects of environmental contaminants and the damage they cause to lift system components.
It is still a further object to provide means for operating the system in safe manner that does not require the driver to take his eyes off the road (to look for and operate switches), and to make the operation of the system automatic and hands-free.
It is a further object to overcome the drawbacks relating to the prior art devices discussed above and to provide at least some of the benefits described below.